Turkish Journal of Fisheries and Aquatic Sciences
2012, Vol 12, Num, 2 (Pages: 253-258)
Effects of Water Temperature and Post-Feeding Period on Postprandial Ammonia Excretion and Oxygen Consumption by Larval Pacific Cod (Gadus macrocephalus) Fed Rotifers (Brachionus plicatilis)
2 Fisheries Resources Research Institute, 1678 Punghwa-Ri, Sanyang-Eup, Tongyeong-Si, Gyeongnam 650-947, Korea
3 Korea Maritime University, Division of Marine Environment and Bioscience, 1 Dongsam-Dong, Yeongdo-Gu, Busan 606- 791, Korea DOI : 10.4194/1303-2712-v12_2_09 Viewed : 4394 - Downloaded : 2877 Postprandial ammonia excretion and oxygen consumption of 15-d post-hatch larval Pacific cod (Gadus macrocephalus), rotifer-fed (Brachionus plicatilis) since their first feeding, were studied in stationary cultures at 10ºC, 13ºC, and 16ºC for 48 h. Postprandial ammonia excretion and oxygen consumption rates were determined after 2, 4, 6, 8, 10, 12, 18, 24, 36 and 48 hours. The 48-h post-feeding weight-specific ammonia excretion and oxygen consumption rates increased until 4 h postfeeding, decreased to 18 h post-feeding, and remained relatively stable until 48 h post-feeding. The highest weight-specific ammonia excretion and oxygen consumption rates were 215±19.8 μg NH3-N g–1 h–1 and 1,778±55.6 μg O2 g–1 h–1 2–4 h postfeeding at 13ºC. The higher (P<0.05) resting ammonia and oxygen consumption at 16ºC 12-h post-feeding indicate that this temperature is not appropriate for inducing higher growth of rotifer-fed pacific cod larvae. Keywords : Pacific cod, larvae, ammonia-nitrogen excretion, and oxygen consumption